Generator driven by drill pipe

ABSTRACT

A rotating control device for sealing about a drill pipe can include a seal which can sealingly engage the drill pipe, and a generator which generates electricity in response to rotation of the drill pipe while the seal sealingly engages the drill pipe. A method of generating electricity from rotation of a drill pipe can include sealingly engaging the drill pipe with a seal of a rotating control device, and generating electricity in response to the rotation of the drill pipe. A system for generating electricity can include a rotating control device which seals about a drill pipe while the drill pipe rotates, the rotating control device comprising a seal and a generator which generates electricity in response to rotation of the drill pipe.

TECHNICAL FIELD

This disclosure relates generally to equipment utilized and operationsperformed in conjunction with a well and, in one example describedbelow, more particularly provides a way of generating electricity due torotation of a drill pipe.

BACKGROUND

Rotation of a drill string is one way to drill a wellbore into theearth. In some situations, a rotating control device is used to seal offan annulus formed between the drill string and the wellbore at or nearthe earth's surface.

It will be appreciated that improvements are continually needed in thearts of drilling wellbores and supplying electrical power to components,such as, sensors, actuators, electronic devices, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a representative partially cross-sectional view of a wellsystem and associated method which can embody principles of thisdisclosure.

FIG. 2 is an enlarged scale partially cross-sectional view of a rotatingcontrol device which can embody principles of this disclosure.

FIG. 3 is a cross-sectional view of the rotating control device, takenalong line 3-3 of FIG. 2.

FIG. 4 is a schematic view of an electrical generation and utilizationsystem which can embody the principles of this disclosure.

DETAILED DESCRIPTION

Representatively illustrated in FIG. 1 is a system 10 for use with asubterranean well, and an associated method, which system and method canembody principles of this disclosure. However, it should be clearlyunderstood that the system 10 and method are merely one example of anapplication of the principles of this disclosure in practice, and a widevariety of other examples are possible. Therefore, the scope of thisdisclosure is not limited at all to the details of the system 10 andmethod described herein and/or depicted in the drawings.

In the FIG. 1 example, a wellbore 12 is drilled by rotating a drill pipe14, such as, by utilizing a drilling rig (not shown) at or near theearth's surface. The drill pipe 14 can be rotated by any means, e.g., arotary table, a top drive, a positive displacement or turbine drillingmotor, etc. Thus, it should be understood that the scope of thisdisclosure is not limited to any particular way of rotating the drillpipe 14.

The drill pipe 14 is part of an overall drill string 16, which caninclude a variety of different components. Preferably, a drill bit 18 isconnected at a distal end of the drill string 16, so that the drill bitcuts into the earth when the drill string rotates and weight is appliedto the drill bit.

An annulus 20 is formed radially between the drill string 16 and thewellbore 12. A drilling fluid 22 (commonly known as “mud,” althoughother fluids, such as brine water, may be used) is circulated downwardthrough the drill string 16, exits the drill bit 18, and flows back tothe surface via the annulus 20.

The drilling fluid 22 serves several purposes, including cooling andlubricating the drill bit 18, removing cuttings, maintaining a desiredbalance of pressures between the wellbore 12 and the surrounding earth,etc. In some situations (e.g., in managed pressure drilling orunderbalanced drilling, or even in conventional overbalanced drilling),it may be desirable to seal off the annulus 20 at or near the earth'ssurface (for example, at a land or sea-based drilling rig, a subseafacility, a jack-up rig, etc.), so that communication between theannulus 20 and the earth's atmosphere or sea is prevented.

For this purpose, a rotating control device 24 can be used to seal aboutthe drill string 16 during a drilling operation. In the example depictedin FIG. 1, the rotating control device 24 is connected to a blowoutpreventer stack 26 on a wellhead 28, but in other examples the rotatingcontrol device could be positioned in or on a riser string, in a subseawellhead, in a wellbore, etc. The scope of this disclosure is notlimited to any particular location of the rotating control device 24.

Referring additionally now to FIG. 2, an enlarged scale partiallycross-sectional view of one example of the rotating control device 24 isrepresentatively illustrated. In this view, it may be clearly seen thatthe rotating control device 24 includes two “passive” seals 30, 32 whichseal against an exterior surface of the drill pipe 14 as the drill piperotates within an outer housing assembly 34 of the rotating controldevice. The FIG. 2 rotating control device 24 may be used with thesystem 10 and method of FIG. 1, or it may be used with other systems andmethods.

In the FIG. 2 example, the outer housing assembly 34 is provided with aflange 36 at a lower end thereof for connection to the blowout preventerstack 26. However, in other examples, the outer housing assembly 34could be provided with suitable connectors for installing the rotatingcontrol device 24 in or on a riser string, to a subsea wellhead, or atany other location.

As depicted in FIG. 2, the lower seal 30 is positioned in the outerhousing assembly 34, whereas the upper seal 32 is positioned in an upper“pot” or enclosure 38. In other examples, either or both of the seals30, 32 could be positioned inside or outside of the outer housingassembly 34, and other numbers of seals (including one) may be used. Thescope of this disclosure is not limited to any particular number orpositions of seals.

As mentioned above, the seals 30, 32 are passive, in that they sealinglyengage the drill pipe 14 whenever the drill pipe is positioned in therotating control device 24, without any need of actuating the seals toeffect such sealing. In other examples, the seals 30, 32 (or either ofthem) could be “active” seals, so that they sealingly engage the drillpipe 14 in response to an applied stimulus.

For example, one or both of the seals 30, 32 could be inflated byintroducing pressure into the seals, an actuator could be used todisplace the seals inward into contact with the drill pipe, etc. Thescope of this disclosure is not limited to any particular manner ofcausing the seals 30, 32 to sealingly engage the drill pipe 14.

In the FIG. 2 example, the seals 30, 32 are mounted to a bearingassembly 40, which is secured to the outer housing assembly 34 by aclamp 42. The bearing assembly 40 includes bearings 44, which permit aninner generally tubular mandrel 46 to rotate relative to the outerhousing assembly 34.

In other examples, a latch mechanism or other device could be used inplace of the clamp 42. The bearing assembly 40 and both seals 30, 32could be positioned entirely within the outer housing assembly 34. Thus,the scope of this disclosure is not limited to any particulararrangement or configuration of the various components of the rotatingcontrol device 24.

Note that, as depicted in FIG. 2, the seals 30, 32 rotate with theenclosure 38 and mandrel 46 relative to the outer housing assembly 34when the drill pipe 14 rotates in the rotating control device 24.Preferably, the drill pipe 14 is grippingly engaged by the seals 30, 32,so that the seals transfer torque from the drill pipe to the mandrel 46.

Rotation of the mandrel 46 by the drill pipe 14 (via the seals 30, 32)operates an electrical generator 48, so that electricity is generated inresponse to the drill pipe rotation. This can be very beneficial incircumstances where electrical power may not otherwise be available ator near the rotating control device 24, there is a desire to reduce oreliminate the use of power cables extending to the area about therotating control device, etc.

In this example, the generator 48 is located in the bearing assembly 40,which is desirably sealed off from well fluids and the atmosphere, andis provided with a lubricant. However, in other examples, the generator48 could be otherwise located, the generator could be exposed to wellfluids or the atmosphere, etc. The scope of this disclosure is notlimited to any particular placement, configuration or environment of thegenerator 48.

Referring additionally now to FIG. 3, a cross-sectional view of therotating control device 24 is representatively illustrated. In thisexample, the generator 48 includes multiple permanent magnets 50 affixedto, and circumferentially distributed on, the mandrel 46.

As the mandrel 46 rotates, the magnets 50 displace by a coil 52. As willbe appreciated by those skilled in the art, a changing magnetic fieldabout the coil 52 (due to the displacement of the magnets 50 by thecoil) will cause electrical current to flow in the coil. The mandrel 46and magnets 50, thus, comprise a rotor 66 of the generator 48, and thecoil 52 and outer bearing assembly 40 comprise a stator 68 of thegenerator 48.

The electrical current generated by the generator 48 can be used tosupply electrical power to any of a variety of different types ofelectrical devices. For example, electrical power could be supplied fromthe generator 48 to electronic circuitry, sensors, actuators, latchingdevices, interlocks, etc. The electrical power can be stored in one ormore batteries for use, for example, when the drill pipe 14 is notrotating in the rotating control device 24.

Although the generator 48 is depicted in FIG. 3 as including the magnets50 and coil 52, in other examples, other means of producing electricalpower could be used. For example, magneto- or electro-strictive devicescould be used to produce electricity in response to rotation of thedrill pipe 14. The scope of this disclosure is not limited to anyparticular way of producing electricity from rotation of the drill pipe14.

In the FIG. 3 example, the single coil 52 remains stationary while themagnets 50 secured to the mandrel 46 displace by the coil. However, inother examples, multiple coils 52 could be used, and/or the coil(s)could be secured to the mandrel 46 or otherwise made to displace by oneor more of the magnets 50.

It may be desired to have the coil 52 displace, for example, if acomponent supplied with electrical power by the generator 48 alsodisplaces. Thus, it should be understood that the scope of thisdisclosure is not limited to any particular location, arrangement orconfiguration of the elements of the generator 48.

Referring additionally now to FIG. 4, a system 54 for generating andutilizing electrical power is representatively illustrated. The system54 may be used with the rotating control device 24 described above, orit may be used with other rotating control devices, or with other typesof well tools.

In the system 54, the generator 48 generates electrical power inresponse to rotation of the drill pipe 14. This electrical power issupplied to a battery 56, sensors 58, electronic circuitry 60, anactuator 62, and an alerting or indicating device 64. However, note thatthese components of the system 54 are merely examples of a wide varietyof different types of devices which can be supplied with electricalpower, and thus, the scope of this disclosure is not limited to use ofthe electrical power by any particular device(s).

In the FIG. 4 example, the sensors 58 could include any type of sensors,such as pressure, temperature, proximity, etc., sensors. For example,the sensors 58 could measure pressure and/or temperature of lubricant inthe bearing assembly 40, pressure and/or temperature of a coolant,pressure and/or temperature of well fluid in the annulus 20 below theseal 30, whether or not the clamp 42 is completely opened or closed,etc. The scope of this disclosure is not limited to use of anyparticular type of sensor.

The electronic circuitry 60 could include at least one processor andother electronic components for monitoring outputs of the sensors 58,controlling operation of the actuator 62, activating the device 64,communicating with external control systems, etc. The scope of thisdisclosure is not limited to any particular use of the electroniccircuitry 60.

The actuator 62 may be used to operate the clamp 42 (or a latching orinterlock mechanism), to actuate “active” seals, etc. The scope of thisdisclosure is not limited to any particular manner of operating theactuator 62.

The device 64 may be used to indicate whether the clamp 42 is open orclosed, whether temperature in the bearing assembly 40 is excessive,whether the seal 30 is leaking, etc. The scope of this disclosure is notlimited to any particular use of the device 64.

The battery 56 can be used to store electrical power generated by thegenerator 48, to condition such power, etc. In this manner, theelectrical power can be available to the sensors 58, circuitry 60,actuator 62 and device 64 whether or not the drill pipe 14 is rotatingat a particular moment.

However, the scope of this disclosure is not limited to use of thebattery 56 for storing electrical power generated by the generator 48.Other electrical storage devices could include relatively large capacitycapacitors (e.g., “super capacitors,” etc.).

It may now be fully appreciated that the disclosure above providessignificant advancements to the art. In an example described above,electrical power is generated in response to rotation of the drill pipe14. Torque is transferred from the drill pipe 14 to the electricalgenerator 48 via the seals 30, 32, which both seal against andgrippingly engage the drill pipe.

The above disclosure provides to the art a rotating control device 24for sealing about a drill pipe 14. In one example, the rotating controldevice 24 can include at least one seal 30, 32 which can sealinglyengage the drill pipe 14, and a generator 48 which generates electricityin response to rotation of the drill pipe 14 while the seal 30, 32sealingly engages the drill pipe 14.

The seal 30, 32 may rotate with the drill pipe 14. In other examples,the seal 30, 32 may not rotate with the drill pipe 14.

The generator 48 can be mechanically coupled to the drill pipe 14 viathe seal 30, 32. In other examples, there may be no mechanical couplingbetween the drill pipe 14 and the seal 30, 32

The seal 30, 32 may grippingly engage the drill pipe 14 and therebytransfer torque to the generator 48. In other examples, torque could betransferred directly from the drill pipe 14 to the generator 48, or viathe mandrel 46, etc.

The seal 30 may be contained in an outer housing assembly 34, and theseal 30 may rotate relative to the outer housing assembly 34 in responseto rotation of the drill pipe 14. In other examples, the seal 30 may notbe contained in the outer housing assembly, and/or may not rotaterelative to the outer housing assembly 34.

The generator 48 may be contained in a bearing assembly 40. In otherexamples, the generator 48 is not necessarily in a bearing assembly.

The generator 48 can comprise a rotor 66 which rotates relative to astator 68 of the generator 48 in response to rotation of the seal 30,32. In other examples, electricity could be generated by other means,such as, electro- or magneto-strictive devices, etc.

The rotating control device 24 may include an actuator 62, and thegenerator 48 may supply electrical power to the actuator 62. In otherexamples, an actuator may not be supplied with electrical power by thegenerator 48.

The rotating control device 24 may include a sensor 58, and thegenerator 48 may supply electrical power to the sensor 58. In otherexamples, a sensor may not be supplied with electrical power by thegenerator 48.

The rotating control device 24 may include a battery 56, and thegenerator 48 may charge the battery 56. In other examples, the generator48 may not charge a battery.

The rotating control device 24 may include electronic circuitry 60, andthe generator 48 may supply electrical power to the electroniccircuitry. In other examples, the generator 48 may not supply electricalpower to electronic circuitry.

A method of generating electricity from rotation of a drill pipe 14 isalso described above. In one example, the method can comprise: sealinglyengaging the drill pipe 14 with a seal 30, 32 of a rotating controldevice 24; and generating electricity in response to the rotation of thedrill pipe 14.

Also described above is a system 54 for generating electricity. In oneexample, the system 54 can include a rotating control device 24 whichseals about a drill pipe 14 while the drill pipe 14 rotates. Therotating control device 24 can include a seal 30, 32 and a generator 48which generates electricity in response to rotation of the drill pipe14.

Although various examples have been described above, with each examplehaving certain features, it should be understood that it is notnecessary for a particular feature of one example to be used exclusivelywith that example. Instead, any of the features described above and/ordepicted in the drawings can be combined with any of the examples, inaddition to or in substitution for any of the other features of thoseexamples. One example's features are not mutually exclusive to anotherexample's features. Instead, the scope of this disclosure encompassesany combination of any of the features.

Although each example described above includes a certain combination offeatures, it should be understood that it is not necessary for allfeatures of an example to be used. Instead, any of the featuresdescribed above can be used, without any other particular feature orfeatures also being used.

It should be understood that the various embodiments described hereinmay be utilized in various orientations, such as inclined, inverted,horizontal, vertical, etc., and in various configurations, withoutdeparting from the principles of this disclosure. The embodiments aredescribed merely as examples of useful applications of the principles ofthe disclosure, which is not limited to any specific details of theseembodiments.

In the above description of the representative examples, directionalterms (such as “above,” “below,” “upper,” “lower,” etc.) are used forconvenience in referring to the accompanying drawings. However, itshould be clearly understood that the scope of this disclosure is notlimited to any particular directions described herein.

The terms “including,” “includes,” “comprising,” “comprises,” andsimilar terms are used in a non-limiting sense in this specification.For example, if a system, method, apparatus, device, etc., is describedas “including” a certain feature or element, the system, method,apparatus, device, etc., can include that feature or element, and canalso include other features or elements. Similarly, the term “comprises”is considered to mean “comprises, but is not limited to.”

Of course, a person skilled in the art would, upon a carefulconsideration of the above description of representative embodiments ofthe disclosure, readily appreciate that many modifications, additions,substitutions, deletions, and other changes may be made to the specificembodiments, and such changes are contemplated by the principles of thisdisclosure. For example, structures disclosed as being separately formedcan, in other examples, be integrally formed and vice versa.Accordingly, the foregoing detailed description is to be clearlyunderstood as being given by way of illustration and example only, thespirit and scope of the invention being limited solely by the appendedclaims and their equivalents.

What is claimed is:
 1. A rotating control device for sealing about adrill pipe, comprising: at least one seal which can sealingly engage thedrill pipe; and a generator which generates electricity in response torotation of the drill pipe while the seal sealingly engages the drillpipe.
 2. The rotating control device of claim 1, wherein the sealrotates with the drill pipe.
 3. The rotating control device of claim 1,wherein the generator is mechanically coupled to the drill pipe via theseal.
 4. The rotating control device of claim 1, wherein the sealgrippingly engages the drill pipe and thereby transfers torque to thegenerator.
 5. The rotating control device of claim 1, wherein the sealis contained in an outer housing assembly, and wherein the seal rotatesrelative to the outer housing assembly in response to rotation of thedrill pipe.
 6. The rotating control device of claim 1, wherein thegenerator is positioned in a bearing assembly.
 7. The rotating controldevice of claim 1, wherein the generator comprises a rotor which rotatesrelative to a stator of the generator in response to rotation of theseal.
 8. The rotating control device of claim 1, further comprising anactuator, and wherein the generator supplies electrical power to theactuator.
 9. The rotating control device of claim 1, further comprisinga sensor, and wherein the generator supplies electrical power to thesensor.
 10. The rotating control device of claim 1, further comprising abattery, and wherein the generator charges the battery.
 11. The rotatingcontrol device of claim 1, further comprising electronic circuitry, andwherein the generator supplies electrical power to the electroniccircuitry.
 12. A method of generating electricity from rotation of adrill pipe, the method comprising: sealingly engaging the drill pipewith at least one seal of a rotating control device; and generatingelectricity in response to the rotation of the drill pipe.
 13. Themethod of claim 12, wherein the seal and generator are components of arotating control device which seals about the drill pipe as the drillpipe rotates.
 14. The method of claim 12, wherein the generating furthercomprises rotating the seal with the drill pipe.
 15. The method of claim12, further comprising mechanically coupling the generator to the drillpipe via the seal.
 16. The method of claim 12, further comprising theseal grippingly engaging the drill pipe and thereby transferring torqueto the generator.
 17. The method of claim 12, wherein the seal iscontained in an outer housing assembly, and wherein the seal rotatesrelative to the outer housing assembly in response to rotation of thedrill pipe.
 18. The method of claim 12, wherein the generator ispositioned in a bearing assembly.
 19. The method of claim 12, whereinthe generator comprises a rotor which rotates relative to a stator ofthe generator in response to rotation of the seal.
 20. The method ofclaim 12, wherein the generating further comprises the generatorsupplying electrical power to an actuator.
 21. The method of claim 12,wherein the generating further comprises the generator supplyingelectrical power to a sensor.
 22. The method of claim 12, wherein thegenerating further comprises the generator charging a battery.
 23. Themethod of claim 12, wherein the generating further comprises thegenerator supplying electrical power to electronic circuitry.
 24. Asystem for generating electricity, comprising: a rotating control devicewhich seals about a drill pipe while the drill pipe rotates, therotating control device comprising at least one seal and a generatorwhich generates electricity in response to rotation of the drill pipe.25. The system of claim 24, wherein the seal rotates with the drillpipe.
 26. The system of claim 24, wherein the generator is mechanicallycoupled to the drill pipe via the seal.
 27. The system of claim 24,wherein the seal grippingly engages the drill pipe and thereby transferstorque to the generator.
 28. The system of claim 24, wherein the seal iscontained in an outer housing assembly, and wherein the seal rotatesrelative to the outer housing assembly in response to rotation of thedrill pipe.
 29. The system of claim 24, wherein the generator ispositioned in a bearing assembly.
 30. The system of claim 24, whereinthe generator comprises a rotor which rotates relative to a stator ofthe generator in response to rotation of the seal.
 31. The system ofclaim 24, further comprising an actuator, and wherein the generatorsupplies electrical power to the actuator.
 32. The system of claim 24,further comprising a sensor, and wherein the generator supplieselectrical power to the sensor.
 33. The system of claim 24, furthercomprising a battery, and wherein the generator charges the battery. 34.The system of claim 24, further comprising electronic circuitry, andwherein the generator supplies electrical power to the electroniccircuitry.